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www.rockproducts.com ROCK products • July 2018 • 31
"When we crush through the cone, those fines return back
and we blend the pit fines with the crusher fines to make
a more consistent crusher-run product, with stable grada-
tion," Boyd said. "If we kicked them out at the jaw, and made
crusher run at the screen, we'd have two separate products;
instead we send both fines products to the screen, where it
blends and mixes and stays consistent."
The feeder itself sets the feed rate for the tons per hour
coming into the plant. "It runs at a higher frequency," Boyd
said. "The prescreener cleans the feed up and keeps the
fines out of the crusher, and that's huge. Instead of being
kicked out the side by conveyor, they go down a chute –
bypassing the crusher – and mix with the crushed material
coming out of the jaw. It cuts down on the wear on the jaw
dies, and the cheek plates. It prevents wear and tear, and
increases throughput."
The prescreen also equates to better fuel consumption.
"These machines literally sip fuel compared to the compet-
itors," Boyd said. "I've been very, very impressed with the
fuel consumption, especially the Kleemann conveyor. They
use hardly any fuel at all and are very reliable."
Closed Circuit Crushing
The interlinked equipment is set up in a closed circuit. Mate-
rial is primary-crushed at the jaw, and both crushed material
and all fines go to the mobile screen.
The MS 15 Z mobile screen has two decks, the top with 2-in.
panels, and 1 1/2-in. panels on the bottom deck. The top deck
overs go to the cone crusher to be sized down (as the jaw is
set to 65 mm, a 4- to 5-in. size rock goes to the cone). The
cone crushes that material and sends it back to the screen
for resizing.
The bottom deck overs are a 2 x 1 1/2-in. rock, and the bottom
deck screen throughs is a 1 1/2 in. size, which is stacked as
a product. Anything dropping through is crusher run, which
is stockpiled and loaded on trucks.
One great benefit of the Kleemann plants is its diesel-elec-
tric drives, Boyd said. "The jaw and the cone are diesel over
electric," he said. "The crushers are run off fluid couplings,
but the rest of the plant is electric. The advantage is that the
electrical systems are much easier to work on; any electrician
Kleemann Mobiscreen operates in closed circuit with jaw and cone.
Kleemann Mobicat MC 110 Zi EVO primary jaw crusher,
Mobiscreen MS 15 Z screen, and Mobicone MCO 9i EVO
secondary cone crusher – all from Kleemann and acquired
in summer 2017 – work together in Interlinked mode.